Usually aerated food products such as ice cream and whipped cream comprise of an oil in water emulsion in which gas bubbles are trapped. Aerated food products need to be stabilised to prevent the product from deflating. Traditionally, saturated fatty acids (SAFA) are used. Common sources of SAFA in ice cream are dairy products such as milk or milk powder. Even skim milk powder usually comprises SAFA. When emulsified and cooled the SAFA are present in the form of small fat globules, present in the bulk of the product (continuous phase) and at the surface of gas bubbles. The SAFA in the bulk are believed to form a network, which stabilises the foam by keeping the gas bubbles separated from each other while the SAFA globules at air/water interface prevent liquid oil droplets from spreading at said interface. However the SAFA are known to be less healthy and there is strong desire to decrease the amount of SAFA in food products. The oil phase in the emulsion could comprise liquid oil. However, liquid oil on the other hand such as triglycerides have pronounced antifoaming action and foam stability decreases with the amount of liquid oil added.
Low molecular weight emulsifiers like lecithin may also be used to keep oil in water emulsion emulsified. Other low molecular weight emulsifiers include polysorbate esters, sorbitan esters, polyglycerol esters, propylene glycol monostearate, sodium and calcium stearoyl lactylates, sucrose esters. However, consumers increasingly avoid such additives.
EP 412 590 discloses denatured whey particles in oil free ice-cream like product but no oil containing aerated products.
Therefore there is a need to for alternative processes and stabilisers to prepare aerated foods like products with decreased amounts of SAFA and low molecular weight emulsifiers.